The problem of two persons lying next to another, without having a place for the two pairs of arms attached to their torsos, is known in the art. In fact, the issue is even joked about in the XKCD comic available, at the time of this writing, at http://xkcd.com/335. In the comic, a mattress is designed which allows the two parties to stick their arms through a hole in the mattress. Then, in a further pane of the comic, the parties are able to play a game with their arms extending through the hole in the mattress.
While not as humorous, in addition to mattresses, pillows with passageways for the arms are also known in the art. For example, U.S. Pat. No. 6,671,907 to Zubari discloses a pillow with two passageways passing through from one narrow side to the other. U.S. Patent to Shaffer U.S. Pat. No. 6,128,797 is for a face-down tanning and massage pad made of an inflatable plastic or rubber material or solid foam material with a center opening and ventilation for holding a person's head in a downward position. U.S. Pat. No. 4,118,813 to Armstrong discloses a sleep training pillow for the prevention of snoring and is designed to train a person to sleep in a position which prevents snoring. The pillow has a pillow-support surface and a face-support surface. The face-support surface is inclined downward from a high end to a low end, and a relief cavity is cut out near the low end of the pillow. U.S. Pat. No. 5,579,551 to Tommaney discloses an arch-shape pillow apparatus provided with an ear accommodation. Hartunian, in U.S. Pat. No. 5,269,035, shows a head support for a person lying in a prone position, which supports the patient's head at the chin and forehead and includes a side opening for an anesthetist to view a patient's face for passage of an endotracheal or other tube used during surgery. Treace, in U.S. Pat. No. 3,694,831 shows a medical head-support for a variety of uses in hospitals. The pillow has two inwardly angled portions, along with a cutout and a hole to position the head facing upward, or downward, or to one side. Further, a variety of U.S. Design Patents (D471050, D636,212, D613,987) and others, as referenced in the Information Disclosure Statement for this patent application, shows various pillow designs.